Q: What is the advantage of rectal aspirin over oral aspirin?
Answer: Faster systemic absorption with suppositories
Aspirin given by rectal suppository is absorbed by the inferior and middle hemorrhoidal veins that eventually drain into the inferior vena cava, avoiding presystemic metabolism through the liver. This will result in early aspirin levels.
Clinical significance: In CVA or acute MI patients where oral or chewable aspirin is not possible due to fear of aspiration, rectal route is as effective, rather quicker in action.
Reference: Nakayasu H, Maeda M, Soda T, et al. The antiplatelet aggregation effects of aspirin suppositories. Cerebrovasc Dis. 2003; 16:31–5.